With a traditional plain old telephone system (POTS), e.g., a wire line based telephone system, it was relatively easy to identify the location of a telephone engaging in a telephone call. A “911” service was created to allow simplified access to emergency services, where simply calling the number would route the caller to the geographically nearest emergency response center and provide the emergency response center with the name and address associated with the calling telephone.
With the advent of mobile telephony, such as cellular telephones, and network based telephony, such as VoIP through wired and wireless networks, area codes and telephone numbers are no longer bound to a particular physical location. The phrases “mobile telephony” and “mobile telephone” will be used to refer to telephony equipment, e.g., phones, computers, etc., not having a fixed location or address, including wireless equipment and equipment communicating over a wired network. Thus, when using mobile telephones, it is difficult to properly identify the source of a telephone call. For example, a wired based approach to identifying a cellular telephone based call may identify the source, e.g., physical location, of the land line used by the cellular telephone company to carry a cellular phone's call, and not the location of the cell phone itself. While some techniques have been created for locating the cellular phone with respect to the towers through with which it is communicating, e.g., triangulation techniques, for a VoIP telephone call, there is not even that option for trying to locate the physical location of a VoIP telephone.
Thus, with mobile telephony, when an emergency call is made to 911, the call will likely be routed to an incorrect emergency response center. Unfortunately, the error may not be minor, instead the call might be connected to a response center hundreds of miles away depending on how the telephone system identified the mobile telephone. In May 2005, however, the Federal Communications Commission (FCC) mandated that VoIP telephone companies provide an Enhanced 911 (E911) service that will provide a mobile telephone's identification and address information to a customer's local emergency response service. Unfortunately, to do so, telephony providers have statically assigned a customer's location information to their mobile telephones. This has a significant drawback because, as indicated above, the phones are mobile and thus may be calling from a location different from what was initially associated with the telephone.